<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <script>
        //边界
//         console.log(/^abc$/.test("abc"));
//         console.log(/^abc$/.test("a"));
//         console.log(/^abc$/.test("ac"));
//         console.log(/^abc$/.test("abcabc"));

		console.log(/^abc$/.test("abc"));
		console.log(/^abc$/.test("ac"));
		console.log(/^abc$/.test("abcd"));
		console.log(/^abc$/.test("abcabc"));

    </script>
</body>
</html>